The source who lead me to this interesting article also mentioned there’d be a “hard limit to how much of an effect lifestyle changes alone can have”.
This assumes that there is no relation between these companies and the individual.

Who These Companies Are

Let’s have a look at who these hundred companies effectively are and why they produce so much emissions:

About every sixth company on the list is a coal company which is used to produce energy for our homes and our workplaces, or e.g. server farms.
If we’d all pay for renewable energy, starting at home, we’d eliminate most of these companies and thus the emissions (which are easily more than 20%) of them already.

Next up, and this about every second company on the list are oil companies. What do we need oil for as individuals? First of all—cars.
Nearly all cars all over the world are running on oil-based fuel.

Airplanes only fly if we feed them with kerosine. And many house-heatings are burning oil to produce heat. Finally, most plastics are made of oil. If we drive less with our cars, share our cars, switch to
smaller cars, fly less, and avoid plastic packaging we’d limit the CO2 emissions. If the companies we lead or work for would do the same,
we’d be easily reduce the carbon footprint by such a high number that our climate would be safe again.

Sure, there’s one more on the list: Gas. We also use it mostly for heating, for some cars, and for technical applications.

“If we don’t consume any goods from these Top 100 companies, we reduce CO2 emissions by 71%.”

The Role Of The Individual

Overall this comes down to the individuals who drive cars, who have a non-renewable energy heating and power their homes, offices and
datacenters with non-renewable energy. If we as individuals can manage to avoid all these companies on the list, our climate would
get about 71% less CO2 emissions. This is currently not possible or would be incredibly hard to achieve but every lifestyle change that
reduces the consumption of petroleum-based products makes a huge impact on our planet’s climate. Which is at high risk.
It looks like we have 11 more years to reduce our emissions back to a level that temperature rises only 1.5 degree until 2100.

Planet earth will not suffer, it can deal with climate change and adapt—but humans will.

Otherwise not only our children but we will soon experience the irreversible effects of climate change. Planet earth will not suffer, it can deal with climate change and adapt—we will.
Climate change is only bad for us humans (and some other species, of course) but not the planet will deal with it as it has done so in the past.
Humans will suffer first and then go extinct. I think it’s as easy as that and if we don’t want this, we need to act quickly and fully as individuals.

One more thing

We need to stop investing into these companies.
When we buy investment fonds, most of them invest heavily in oil/gas/coal and also arms industry companies.
We all want to save money but at which cost? Let’s choose greener options, there are fonds that are not harming the planet or humanity as much while being as profitable as ‘traditional’ ones.